One of the most popular vehicles in use today is the pickup truck. In addition to providing many different occupations with the necessary means by which to transport materials and equipment, pickup trucks are also widely used by persons who simply desire a mode of transportation that can conveniently transport additional items when needed. It is because of the varied uses of pickup trucks that so many different types and sizes are available. Even with the variety of pickup trucks that may be chosen, from those that are considered small or "light" trucks to the larger, heavy-load, dually models, all pickup trucks share certain characteristics.
The most obvious and noticeable characteristic is that all pickup trucks have a bed. The only differences in bed design are that a truck may have either a long bed or a short bed, or a truck can have the more popular and conventional enclosed bed or what is known as a flat bed, which is used almost exclusively for transportation of materials and/or equipment.
For pickup trucks with enclosed beds there is almost always a rear opening with a door-like structure known as a tailgate.
The purpose of the tailgate is to maintain the truck's bed enclosed on all sides, while still allowing access to the bed without the need for going over every wall structure. This is accomplished by having the tailgate hinged on its lower edge. A latch, which is usually located near the upper edge of the tailgate, keeps the tailgate securely closed.
Inevitably, unscrupulous persons realized that pickup trucks tailgates were valuable parts of a truck, and were relatively easy to steal. Additionally, once a tailgate is removed there is much easier access to whatever may be located in the truck's bed. As a result of this there have been attempts made to provide some means of locking a pickup truck tailgate. Unfortunately, not all of these devices function adequately, and therefore tailgates are still being stolen, much to the dismay of their owners. Obviously, if there were some way of efficiently and securely locking a tailgate, that could be purchased as an aftermarket accessory and was easy to install, it would be a great benefit to pickup truck owners.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention however, the following U.S. patents were considered related:
U.S. Pat. No. INVENTOR ISSUED 5,104,171 Johnsen 14 April 1992 5,004,287 Doyle 2 April 1991 4,529,351 Olins 16 July 1985 4,358,l50 Nash 9 November 1982
The U.S. Pat. No. 5,104,171 discloses a tailgate guard assembly which incorporates a metal plate that closes off the handle recess. The plate is stiffened by an inwardly extending skirt welded to the back of the plate so that the skirt projects into the handle recess to hinder direct access into the handle recess under the edge of the plate. A hinge section along the top edge of the plate hooks in behind the outer panel of the tailgate along the top of the handle recess. A lock disposed near the lower end of one of the sides of the handle recess has a locking dog that rotates to a locking position in which it latches behind the outer panel of the tailgate without any structural modifications or additions to the tailgate.
The U.S. Pat. No. 5,004,287 discloses a locking device that is provided for a removable tailgate on a pickup truck. The tailgate assembly is supported by a pair of hinges located at the bottom of the tailgate. One of the hinges comprises an elongated pin member and receiver cup, the pin member extending from the truck body into the receiver cup located in the tailgate. An opening is provided in the side wall of the receiver cup to allow the pin member and consequently the tailgate to be removed when the opening is aligned with the narrow axis of the pin member. A cylinder lock and lock bolt is attached to the tailgate, the lock bolt extending through the end wall of the receiver cup. Upon engaging the lock, the lock bolt projects through the end wall of the receiver cup into an opening provided in the axis of the pin member, thereby allowing the tailgate to be locked to the pickup truck body while concurrently allowing the tailgate to be freely opened and closed along the horizontal axis of the hinges.
The U.S. Pat. No. 4,529,351 discloses a tail-gate assembly comprising a stationary support, a slide mounted on the stationary support, a platform pivotally mounted on the slide, a latch member mounted on and projecting laterally from the loading platform and a latch plate mounted on the stationary support. The notch is proportioned to receive the latch member in a close fitting relationship so as to provide a vertical restraint limiting vertical movement and a rotational restraint limiting rotational movement of the platform. A pair of latching jaws each having a locking tooth at one end thereof, are mounted on the latch plate for pivotal movement between a closed position in which the locking teeth extend inward from opposite sides of the entrance way to prevent withdrawal of the latching member from the notch and an open position in which the teeth are displaced outward from the entrance way to admit and release the latching member.
The U.S. Pat. No. 4,358,150 discloses a vehicle tailgate handle latch mechanism which includes a pair of latch assemblies carried by casings adapted to be fixed adjacent each side of the tailgate for engagement with an associated striker member on the vehicle body. A central lift handle rotates control rods about their axis such that the ends release pawl elements of their associated latch assemblies causing spring biased ratchet members to automatically rotate to a then open position unlatching their strikes allowing the tailgate to be moved to its open position.
For background purposes and as indicative of the art to which the invention relates, reference may be made to the following remaining patents found in the search:
 U.S. Pat. No. INVENTOR ISSUED 4,981,320 Bowman 1 January 1991 4,968,084 Asher, etal 6 November 1989 4,819,461 Pearson 11 April 1989